Most the temples have performances of dance forms like Kathakali, Kuttiyattam and Mohiniyattam during festivals and could be watched to experience the culture of the Kerala. Margi Theatre is a prominent institution which holds these performances in Trivandrum regularly. You may also enquire about dance and music shows which are organized by the Sangeetha Natak Academy. You should also enquire about performances of Kalarippayat done by CVN Kalari Sangham. Onam is celebrated with a lot of fanfare in September- October in Trivandrum, so Arattu at Sri Padmanabha Swamy Temple. Other culturally important festivals celebrated in Trivandrum are Nishagandhi Dance and Music Festival, Attukal Pongala, Flower Show and Swathi Sangeethotsavam.